Pulverizing or grinding mill



April 1, 1930. D. UHLE ET AL 1,752,623

PULVERIZING OR GRINDING MILL Filed NOV. 22, 1928 2 SheetsI-Sheet 1 INVENTORS DAVID J. UHLE J06EPHVDURN\N,-

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April 1., 1930. D. J. UHLE ET AL PULVERIZING OR GRINDING MILL Filed Nov. 22, 1928 2 Sheets-Sheet 2 Lyy'ggd I1\ IVENTOR5 DAVID J. UHLE JOSEPH V. DURNIN,

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A TTORNEY.

Patented Apr. 1, 1930 UNITED STATES PATENT OFFICE DAVID J. UHLE AND JOSEPH V. DUBNIN, OF ALLENTOWN, PENNSYLVANIA PULVERIZING R GRINDING MILL Application filed November 22, 1928. Serial No. 321,207.

Our invention relates to improvements in pulverizin or grinding mills, and has particular reirence to improvements in the grinding ball pushing means or yoke of such mills.

V In accordance with our invention, pushing means, preferably in the form of a rotatable yoke is provided, which is secured to and driven by the usual drive shaft. Th s yoke has outwardly extending arms carrying reciprocatory slidable pusher elements, which have spherically curved convex or forwardly tapered'faces, for engaging with the grinding balls, and affording the minimum contacting surfaces between the same. The reciprocatory pusher elements are free to turn upon their axes, and are urged forwardly by yielding means, such ascompressible coil springs.

In the accompanying drawings, forming a part of this specification, and in which like numerals are employed to designate like parts throughout the same,

Figure 1 is a central vertical longitudinal section through a mill embodying our invention Figure 2 is a horizontal section taken on line 2'2- of Figure 1,

Figure 3 is a similar view taken on line '3-3 of Figure 1, r V

Figure 4 is a plan view of the yoke and associated elements, 7 p

Figure 5 is a side elevation of the same,

Figure 6 is an enlarged fragmentary plan view of one of the rotatable arms of the yoke and the pusher element,-

Figure 7 is a side elevation of the same, and,

Figure 8 is a longitudinal section taken on line 8-8 of Figurel.

The yoke and associated elements constituting the principal feature of the present invention, are particularly adapted for use in connection with the pulverizing or grinding inilhshown Letters Patent No. 922,468 under date of'May 25, 1909,-to J. W. uller, Jr. The 'mill embo'dies generally a casing 10, within which is arranged a grindring 1-1, having a transversely curved en- "mi ar recess 12, within which travels the grinding M11514. The upper casin section isupon'the casing 10, an a screen 16 is disposed within the casing section 15 and spaced therefrom, with a coarser pro tecting screen 17, disposed inwardly of the first named screen. The pulverized or ground material which passes the screen 16 dis- 5 charges into a passage 18, and descends through the passage 19 and finally discharges through an outlet 20. The numeral 21 designates a feed hopper, which discharges the material into the upper portion of the casing 15,

inwardly of the screen 17.

The numeral 22 designates a vertical drive shaft, journaled inbearings 23 and 2 1, and driven by a pulley 25. As this construction 7 is identical with that shown in Patent No.

The pusher element 30 not only is free to move longitudinally within the bushing, but

is free to turn upon its longitudinal axis.

The convex end of the pusher element, which contacts with the grinding ball, is rendered a hard by any suitable means. As illustrating one way in which this hardening of the convex face may be effected, we contemplate placing a covering 11 of high speed tool steel upon the pusher element, the same being welded thereto, although the convex face may be hardened by any other suitable means. By virtue ofithe convex face of the pusher ele ment, the minimum contact surface is afforded between the pusher element and the grinding ball and this permits of the freespinning d of the grinding ball. The convex surfaces of the ball and pusher element also permit of the free outward movement of the ball,due to the wearing down of the rinding ring, and

the radial movements of e ball, dueto the.

shifting of the same by different thicknesses of material being ground.

The pusher element is provided with a reduced stem 32 passing through a contracted opening 33 in the arm. This reduced stem provides a shoulder 34. A compressible coil spring 35 surrounds the stem 32 and is arranged within the recess 28, and engages the shoulder 34, to force the pusher element 30 :lorwardly. A lubricating opening 36 is provided in the top of the arm 27 and is closed by a plug 37 The stem 32 is provided with a nut 38 or the like to limit the forward movement of the pusher element.

The upper end of the hub 26 of the yoke is preferably beveled, as shown at 43, to deflect material to be ground toward the grinding balls 14. Formed integral with the hub 26 near the upper end thereof are spaced horizontal radial arms 44, arranged at an elevation above the arms 27, and staggered with relation thereto.

' The numeral designates a fan or blower as a whole, including a lower ring 46, carrying outwardly projecting radial lugs 47, bolted to the arms 44, as shown at 48. Formed integral with the ring 46 are spaced vertical arms 49, carrying upper vertically arranged blades or paddles 50, integral therewith. The blades are disposed at the leading edges of the vertical arms 49 and are further connected therewith by tapered webs 51, integral therewith. The vertical blades 50 rotate adjacent to the screens 16 and 17 and serve to throw the ground material through or toward the same. The numeral 52 designates lower elevating blades or paddles which are inclined and have their lower ends extending in an elevation beneath the lower ends of the vertical blades 50. The lower elevating blades 52 are preferably provided at their outer edges with upstanding longitudinal flanges 53. The blades 52 are formed integral with the ring 46, and webs 53 reinforce and connect these parts, and are formed integral therewith. The elevating blades 52 operate above and near the grinding balls 14 and serve to raise the powdered or ground material, which is brought into the path of travel of the vertical centrifugal blades 50 and thrown thereby toward the screen 16.

In the operation of the mill, the material is fed into the central portion of the same, through the hopper 21 and passes to the grinding balls 14, traveling upon the grinding rings. The pusher elements, by virtue of their convex faces, have the minimum area of contact with the grinding balls and hence the grinding balls are free to spin during their travel. The pusher elements being spring supported, the shocks or hammering actions are absorbed, particularly upon starting the mill. Further, the yielding support of the pusher element, prevents the breaking of the yoke arms, carrying the same. Further, the yielding support of the pusher elements, combined with their convex faces, affords a free spinning action for the grinding balls, resulting in the better operation of the mill and the increased life of the grinding balls and associated elements. The shaft 22 is driven at a suitably high speed and the elevating blades 52 serve to draw the ground or powdered material upwardly and through the same into the path of travel of the vertical or centrifugal blades 50, which in turn throw the same toward or through the screens 16 and 17. It is thought that no further detailed description of the operation of the machine is necessary.

It is to be understood that the form of our invention, herewith shown and described, is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts, may be re sorted to without departing from the spirit of our invention, or the scope of the subjoincd claims.

Having thus described our invention, we claim 1. In a grinding mill, a casing, a grinding ring arranged within the casing, a rotatable support arranged within the casing, reciprocatory pusher elements carried by the support and having convex faces to engage with the grinding balls, and yielding means to oppose the longitudinal movement of the pusher elements in one direction.

2. In a grinding mill, a casing, a grinding ring arranged within the casing, grinding balls operating upon the grinding ring, a retatable support arranged within the casing, reciprocatory pusher elements mounted upon the support and adapted to turn upon their axes with relation thereto, said pusher elements having convex contact faces, and yielding means to oppose the longitudinal movement of the pusher elements in one direction.

3. In a grinding mill, a casing, a grinding ring arranged within the casing, grinding balls operating upon the grinding ring, a rotatable support arranged within the casing, reciprocatory pusher elements mounted upon the support and being permanently free to turn upon their longitudinal axes with relation thereto, and yielding means to oppose the longitudinal movement of the pusher elements in one direction.

4. In a grinding mill, a casing, a grinding ring within the casing, grinding balls engaging the grinding ring, a rotatable support, reciprocatory pusher elements mounted upon the support and being permanently free to turn upon their longitudinal axes with relation to the support and having their engag ing faces so shaped that they afford the mini mum contacting surfaces with the grinding al a d yield mean to po the 1 1- gitudinal movement of the pusher elements in one direction.

5. In a grinding mill, a casing, a grinding ring arranged within the casing, grinding balls operating upon the grinding ring, a drive shaft extending between the grinding balls, a yoke carried by the drive shaft and embodying approximately radial arms having transverse recesses, reciprocatory pusher elements mounted within the transverse recesses and being permanently free to turn upon their longitudinal axes with relation to said arms, and springs arranged within the transverse recesses and engaging the pusher elements to force them forwardly.

6. In a grinding mill, a casing, a grinding ring within the casing, grinding balls operating upon the grinding ring, a drive shaft extending between the grinding balls, a yoke carried by the drive shaft and having radial arms provided with transverse recesses, each recess being open at its forward end and having a bottom wall at its rear end provided with a contracted opening, a reciprocatory pusher element mounted within each recess and being permanently free to turn upon its longitudinal axis with relation to its arm, a contracted stem secured to the pusher element and extending through the recess and through the contracted opening in the bottom wall, said stem forming a shoulder with the pusher element, a compressible coil spring arranged within the recess and surrounding the stem and confined between the bottom wall and said shoulder, said spring being entirely enclosed within the recess, said pusher element being arranged to engage with the adjacent grinding ball and means to limit the forward movement of the pusher element with relation to the arm.

In testimony whereof we aflix our signatures.

DAVID J. UHLE. JOSEPH V. DURNIN. 

